SPAX Decking Screws (12G) 6mm x 50mm A4 316 Stainless Steel 0538000600503
The screw councils, parks & pro crews trust
Double-thread fixing
The upper fixing thread pulls the board tight to the joist — no squeaks, no popped heads.
T-STAR plus T-25 drive
Positive bit engagement means almost no cam-out and far fewer chewed heads on a long run.
CUT point — no pre-drill
The serrated cut tip pushes timber fibre aside, reducing splitting on most hardwoods.
A2 / 304 stainless
Corrosion-resistant for exposed decks. Step up to A4/316 for coastal and saltwater jobs.
How many screws will your deck need?
Enter your deck size and board width — we'll work out the screws and packs.
Which length do I need?
Rule of thumb: the screw should penetrate the joist by at least 2× the board thickness without poking through.
| Board thickness | Recommended length | Typical use |
|---|---|---|
| 12–16mm | 40–50mm | Thin profile / cladding |
| 19–21mm | 60mm | Standard decking board |
| 22–28mm | 70mm | Heavy / wide boards |
| 30mm+ | 80mm | Bearers, thick hardwood |
Full spec sheet
| Length | 50mm |
|---|---|
| Thread diameter | 6.0mm |
| Head diameter | 7.0mm |
| Maximum board thickness | 19mm |
| Partial thread length | 23.0mm |
| Head type | Cylindrical head (countersinks flush) |
| Drive | T-STAR plus T-25 |
| Thread type | Fixing thread |
| Tip | CUT point — reduced splitting |
| Material | A4 316 Marine Grade Stainless Steel |
| Pack quantity | 100 screws |
| Origin | Made in Germany |
Before you buy
Do I need to pre-drill?
For most softwoods and many hardwoods, no. Near board ends or in dense hardwoods like Merbau, a quick pilot hole is good insurance.
304 or 316 stainless — which one?
A2/304 suits standard exposed decks. Within a few hundred metres of saltwater, step up to A4/316.
Is shipping really free?
Yes — this pack is over our $199 threshold, so delivery is free Australia-wide. Order before 2pm AEST for same-day dispatch.
Can I get a trade price on bulk?
Yes. For multiple tubs or a full job, open a trade account or call us for volume pricing.